Jersey Amber Research Articles

FOSSIL OONOPID SPIDERS IN CRETACEOUS AMBERS FROM CANADA AND MYANMAR

Abstract: The spider family Oonopidae is described from Cretaceous ambers from Myanmar and Canada for the first time. Orchestina albertenis sp. nov. is the first spider to be described from Canadian Grassy Lake amber and only the second spider to be described from Canadian amber. The specimen in amber from Myanmar extends the known range of the extant genus Orchestina back another 10 million years from the previously oldest specimen in Turonian New Jersey amber. Despite being unknown as sedimentary fossils, Oonopidae occur in more fossil deposits than any other spider family and were already widespread by the Cretaceous. The family contains the oldest example of an extant spider genus along with Archaeidae, also from Burmese amber.

THE FOSSIL SPIDER FAMILY LAGONOMEGOPIDAE IN CRETACEOUS AMBERS WITH DESCRIPTIONS OF A NEW GENUS AND SPECIES FROM MYANMAR

The spider family Lagonomegopidae was described a decade ago from two specimens in Upper Cretaceous Siberian amber from the Taimyr Peninsula, and placed in the superfamily Palpimano- idea. Lagonomegopidae is known only from Cretaceous amber. Undiscovered extant species are considered unlikely because of their frequent occurrence in Cretaceous ambers and their absence in Tertiary fossil resins. One aim of this paper is to bring the existence of this family to the attention of neo-arachnologists. Burlagonomegops eskovinew genus and species is described from Cretaceous amber of Myanmar (Burma) and Lagonomegops americanusnew species is assigned to a previously described, but unnamed specimen from Cretaceous New Jersey amber.

Primitive New Ants in Cretaceous Amber from Myanmar, New Jersey, and Canada (Hymenoptera: Formicidae)

New information is provided on the oldest fossil ants (Formicidae), including the description of a new species of †Sphecomyrma (†Sphecomyrminae), a new genus of sphecomyrmines, a new genus of apparent myrmeciines, and a new genus of apparent aneuretines. New material from New Jersey amber (Turonian) includes workers of †Sphecomyrma freyi Wilson and Brown preserved together in the same piece of amber, a worker of an unidentifiable †Sphecomyrma species, and a worker of †Brownimecia clavata Grimaldi, Agosti, and Carpenter (†Brownimeciinae). A new species of †Sphecomyrma in New Jersey amber is described and figured from a worker as †S. mesaki, new species. Two worker specimens in Campanian amber from Canada are described, one of which is described as †Cananeuretus occidentalis, new genus and species, and is tentatively placed in Aneuretinae. From Burmese amber (Albian-Cenomanian) are the oldest, definitive ants, along with ones in amber from Charente-Maritime of France (approximately contemporaneous in age). A new genus and species, allied to †Sphecomyrma, is described from these deposits as †Sphecomyrmodes orientalis, along with a remarkable new “poneroid”, †Myanmyrma gracilis, new genus and species (Myrmeciinae?). A key to the species of †Sphecomyrma is provided, the classification of ants summarized, and the Cretaceous records of Formicidae briefly outlined.

A formicine in New Jersey cretaceous amber (Hymenoptera: formicidae) and early evolution of the ants.

A worker ant preserved with microscopic detail has been discovered in Turonian-aged New Jersey amber [ca. 92 mega-annum (Ma)]. The apex of the gaster has an acidopore and, thus, allows definitive assignment of the fossil to the large extant subfamily Formicinae, members of which use a defensive spray of formic acid. This specimen is the only Cretaceous record of the subfamily, and only two other fossil ants are known from the Cretaceous that unequivocally belong to an extant subfamily (Brownimecia and Canapone of the Ponerinae, in New Jersey and Canadian amber, respectively). In lieu of a cladogram of formicine genera, generalized morphology of this fossil suggests a basal position in the subfamily. Formicinae and Ponerinae in the mid Cretaceous indicate divergence of basal lineages of ants near the Albian (ca. 105-110 Ma) when they presumably diverged from the Sphecomyrminae. Sphecomyrmines are the plesiomorphic sister group to all other ants, or they are a paraphyletic stem group ancestral to all other ants-they apparently became extinct in the Late Cretaceous. Ant abundance in major deposits of Cretaceous and Tertiary insects indicates that they did not become common and presumably dominant in terrestrial ecosystems until the Eocene (ca. 45 Ma). It is at this time that modern genera that form very large colonies (at least 10,000 individuals) first appear. During the Cretaceous, eusocial termites, bees, and vespid wasps also first appear-they show a similar pattern of diversification and proliferation in the Tertiary. The Cretaceous ants have further implications for interpreting distributions of modern ants.

The oldest fossil bee: Apoid history, evolutionary stasis, and antiquity of social behavior

Trigona prisca, a stingless honey bee (Apidae; Meliponinae), is reported from Cretaceous New Jersey amber (96-74 million years before present). This is about twice the age of the oldest previously known fossil bee, although Trigona is one of the most derived bee genera. T. prisca is closely similar to modern neotropical species. Most of bee evolution probably occurred during the approximately 50 million years between the beginning of the Cretaceous when flowering plants (on which bees depend) appeared and the time of T. prisca. Since then, in this phyletic line of Meliponinae, there has been almost no morphological evolution. Since the fossil is a worker, social organization had arisen by its time.